Presence, Proximity & Distance Sensing for Smart City

Small, fast and lightweight single-pixel and multi-pixel sensors for People or Vehicle Counting, Smart Lighting, Smart Parking, Smart presence and many more smart city applications.


Customizable Sensing for Smart City Technology

Terabee technology (branded TeraRanger) is a modular and flexible sensing platform delivering high performance at lower cost. Born for robotics, and now supporting smart city, our ‘technology bricks’ can be organized, optimized and industrialized to meet your specific needs.


Key Features

  • Single-pixel and multi-pixel (3D)
  • Plug and play simplicity – Use one sensor, or many
  • Support for LoRA, SigFox, WiFi, Bluetooth…
  • Embedded intelligence for custom data output
  • Customizable; power supply, connectors, IP67 enclosures…

Smart parking sensors



TeraRanger Advantages

TeraRanger smart city sensors are small and lightweight, but pack a powerful performance punch!

The maximum reading distance is up to 60 meters and for some sensors data update rates can be as high as 1000 readings per second. Typical weight of a sensor is just 8 to 12 grams.

By using active LED illumination TeraRanger sensors do not rely on external illumination and can operate in a broad range of conditions, including sunlight. Our LED technology remains eye-safe in all conditions, while still attaining long-range.

A simple Plug and Play approach to using multiple sensors on a single power and data hub makes it easy to setup sensor arrays for multi-axis and multi-sensor use.

TeraRanger sensing city technology is ideal for: sensing for smart city, presence, proximity and position sensing city; object recognition, counting, profiling, distance, speed and velocity sensing.


Added Intelligence

At your request, algorithms and intelligence can be added for on-board processing, or the data can be processed on companion computers or centralized infrastructures.


Intelligence and Sensing for Robotics

Small, lightweight, high-performance 2D and 3D robotic Time of Flight sensors and
solutions for monitoring, mapping, SLAM, collision avoidance and many more robotics applications!


TeraRanger Advantages

Using LED Time-of-Flight, Terabee technology (branded TeraRanger) includes small, lightweight and high-performance distance and ranging ir sensors for robots. The maximum reading distance is up to 60 meters and for some sensors data update rates can be as high as 1000 readings per second. Typical weight of a sensor is just 8 to 12 grams. TeraRanger offers plug and play simplicity and cross-talk avoidance when using multiple sensors.


application of sensors in roboticsSelective Point Cloud

A simple Plug and Play approach to using multiple sensors on a single power and data hub makes it easy to setup custom sensor arrays for multi-axis, multi-sensor use, and gather a selective point cloud for your control system.

TeraRanger technology is ideal for airborne and ground-based mobile robotics, including Drone altimeter and collision avoidance sensors for robotics ; Mapping and navigation sensors; Simultaneous Localization and Mapping (robotics SLAM).

For industrial robotics we enable: Presence and position monitoring; Object recognition sensors; Counting and profiling; Access protection and human-machine interface.


Customizable Sensing for Robotics

Terabee technology is a modular and flexible sensing platform delivering high performance at lower cost. Born for robotics our ‘technology bricks’ can be quickly organized, optimized and industrialized to meet your specific needs.



Intelligence and Sensing for Drone Operations

Fast, lightweight, high-performance Time of Flight sensing for drone operations.
Precision altimeter : Obstacle avoidance sensor : Drone anti collision : Pilot aid : Vision systems aid


TeraRanger Advantages

Using LED Time-of-Flight, Terabee technology (branded TeraRanger) includes small, lightweight and high-performance distance and ranging sensors for drone operations. The maximum reading distance is up to 60 meters and for some TeraRanger Time-of-Flight sensors data update rates can be as high as 1000 readings per second. Typical weight of a sensor is just 8 to 12 grams. TeraRanger offers plug and play simplicity and cross-talk avoidance when using multiple sensors. 


Key features

  • Compact sensing for drones, lightweight design
  • Fast refresh rates (up to 1kHz)
  • Stable distance data acquisition over irregular-shaped surfaces (crops and trees, etc.)
  • Plug and Play simplicity
  • Compatible with Pixhawk flight controllers
  • CE certified and eye-safe
  • Works indoors and outdoors


Product benefits

sensing for drone

Precision altimeter

  • Stable altitude hold and height control
  • Terrain following
  • Auto landing for multirotor, helicopter, fixedwing, etc

Drone collision avoidance

  • Increase safety when flying close to obstacles
  • Maintain fixed distances from objects during inspection
  • Avoid obstacles indoors and outdoors

Complement to vision systems

  • Add scale to vision data



Drone obstacle avoidance indoor flight

Obstacle avoidance drone

Drone obstacle avoidance indoor drone

In this use case, you’ll see TeraRanger Tower and TeraRanger Evo enabling drone with obstacle avoidance indoor flight (GPS-denied). A single TeraRanger Evo controls the altitude of the drone whilst TeraRanger Tower prevents the drone from flying into static and dynamic obstacles.

This configuration is compatible with Pixhawk running ArduCopter. See our detailed post here for full setup details and instructions.

If you require robust solutions for indoor drone collision avoidance flight, please contact us. We will be happy to explore your requirements with you.

Featured product: TeraRanger Evo

Click “Learn More” for specification sheets, user manuals, software and other resources.


TeraRanger Evo is the long-range Time-of-Flight distance sensor of the TeraRanger product family.

Featured product: TeraRanger Tower

Click “Learn More” for specification sheets, user manuals, software and other resources.


TeraRanger Tower is a simultaneous multi-axis scanner for SLAM and drone collision avoidance and drone object avoidance capable of replacing traditional laser lidar scanners in some applications.

Obstacle avoidance for indoor drone flight!

Recently we evaluated performance of indoor obstacle avoidance on a quacopter with Pixhawk running ArduPilot and equipped with a TeraRanger Tower and TeraRanger Evo distance sensor for drones. This report presents our setup and the results.

Parts used:

Obstacle avoidance indoor drone

Drone object avoidance in Arducopter

In version 3.5, ArduCopter introduced object avoidance in Loiter and AltHold modes. By using TeraRanger Tower you can implement the object avoidance feature on your aircraft.

In both Loiter and AltHold modes the area around the vehicle is divided into 8 sectors, with sector 0 pointing forward by default:

Obstacle avoidance for indoor drone flight - 8 detection areas

When setting up the TeraRanger Tower on the drone it is important to make sure that the sensor labeled on the TeraRanger Hub PCB board as TR0 is the one that is pointing forward.

TeraRanger Tower setup

When mounting the tower on the drone it is important to take into account the 3 degrees Field of View of the TeraRanger sensors and their emitted light to ensure that the Field of View is not obstructed by the aircraft frame or propellers. For safety, we usually mount the sensors with about 15 degrees clearance (see picture below).

drone collision avoidance - field of view

If you are not sure if your propellers are in the Field of View of the sensor you can perform a static test using the TeraRangerHub GUI and manually change propeller positions to see if the readings are affected.

We connected the Tower to Pixhawk following this diagram (make sure you are connected to U3 port on the TeraRanger Hub board):

Drone obstacle avoidance Pixhawk - hub connection

To provide power to the board we made a connection between the drone power distribution board and the U1 port on the TeraRanger Hub PCB. With this setup we are using unregulated battery power (10-20V is the accepted voltage of TeraRanger Hub). Since we are using 3S LiPo batteries the voltage provided to the board is within range (~12.60V when the battery is fully charged).

TeraRanger Evo – Altimeter setup

In our setup we use a TeraRanger Evo as an altimeter. At the time of writing, the Evo drivers hadn’t made it to the official ArduCopeter 3.5 release, however, they are supported on the development branch (instructions on getting the development version can be found in chapter 3.2 of our connection instructions).

Obstacle avoidance Pixhawk - Evo connection

Evo i2c backboard pins Pixhawk i2c port pins
1 Tx
2 Rx

Obstacle Avoidance in Loiter mode

We originally showed object avoidance in Loiter mode in our video last year: 

In Loiter mode, thanks to sensor data filtering and position information from GPS, the autopilot has high-quality information on it’s speed and acceleration with respect to the ground (groundspeed and groundacceleration). By using a sensor array system, such as TeraRanger Tower, the autopilot can get information on how far away it is from obstacles that are in the sensors fields of view. Knowing how fast the multirotor is travelling towards the obstacle, and having precise distance information from said obstacle, allows the autopilot to request a horizontal acceleration in time to stop the drone at a predefined distance from the obstacle. Since this mode is highly dependent on position information (usually obtained from the GPS) it will not work if GPS is not available, but could potentially harness other positioning systems like an optical flow camera, or motion capture system.

Drone obstacle avoidance in Altitude Hold

Things get very interesting with Altitude Hold mode. Since there is no position reference system (e.g. GPS) we don’t have precise information about where our drone is and in which direction it is actually flying.

Imagine flying a multirotor in a mode in which you have full control over thrust and roll and pitch angle. Let’s say that with 50% thrust you can keep your multirotor level at a fixed height, in such a case the generated thrust is in equilibrium with the aircraft weight. As soon as our aircraft has some roll angle, assuming you don’t increase thrust, your aircraft will start descending as the upward component of the thrust vector is not in equilibrium with the aircraft weight. The remaining thrust component will make the drone fly in the direction of roll. This concept is illustrated on the figure below.

obstacle avoidance sensor

By using altitude hold for indoor drone obstacle avoidance ArduCopter developers can ensure that the appropriate thrust is applied by the motor, so when the multirotor is banking or pitching we can be sure that the autopilot will do it’s best to keep the aircraft at the requested height. You can use a barometer for this task, however by using a TeraRanger rangefinder you will see much better performance in holding a fixed height.

As mentioned earlier in this case, the Pixhawk obstacle avoidance does not know how fast the drone is travelling but it can keep the fixed height. The obstacle avoidance has been solved by ArduCopter developers by creating a pitch/roll request based on the distance measurements received from all the sensors. The largest positive and negative roll and pitch angles are found and combined together resulting in a final roll/pitch angle. Those combined roll/pitch values are then fused with the pilot input. [Source:].

At the time of our tests, the object avoidance library can request a lean angle of 75% of the maximum allowed lean angle (If you were to set ANGLE_MAX to 1000 centidegrees than the maximum transmitter stick input will translate to 10 degrees, while the input from the avoidance library will not be larger than 7.5 degrees). That means that, if you asked for a 75% roll command, thoeretically the aircraft should be level at the minimum distance set from the obstacle. This is not necessarily good! As discussed earlier, since the autopilot has no precise information on aircraft speed, your aircraft might be perfectly level but still have velocity in a horizontal direction! That is why we advise you, if you want to test the obstacle avoidance drone in Altitude Hold, to take it slow and build trust in the system first.

Usually, when AltHold mode is concerned, we advise our customers to set the AVOID_ANGLE_MAX and ANGLE_MAX to relatively low values. AVOID_ANGLE_MAX is the maximum angle that might be requested by the Object Avoidance library and ANGLE_MAX is the maximum lean angle in all flight modes.

Highlight of parameters of Altitude Hold mode

Here is a short highlight of the parameters we set on the Pixhawk that you see in the original video:

  • ANGLE_MAX: 1000
  • RNGFND_MAX_CM: 60000
  • SERIAL4_BAUD: 921

You can get our parameter file here.


TeraRanger Tower and TeraRanger Evo, when combined with Pixhawk running ArduCopter firmware, provide a strong solution for drone object avoidance in GPS-denied environments. The system is easy to set up and integrate. We advise any integrator to start tuning the system by setting small values of AVOID_DIST_MAX and ANGLE_MAX parameters, to get a good feel for the functionality, before making the system more aggressive.


Arducopter Object Avoidance wiki:

TeraRanger Tower Avoidance wiki:

TeraRanger One Rangefinder wiki:

TeraRanger Evo Pixhawk instructions:


Drone precision altimeter with TeraRanger One!

TeraRanger distance sensors are ideally suited for use in drone applications, and in particular as a ‘drone precision altimeter’. The small size, light weight (8g), fast update rates and plug and play compatibility with autopilots, make the sensors the first choice for many professional drone builders. Here are some examples:

AirDog – The All-Terrain Autonomous Flying Action Sports Drone

TeraRanger One is used on AirDog II for rapid terrain tracking! It enables the high-speed drone precision altimeter to follow people as they perform their sports, without the drone crashing into the ground. Imagine a skier or mountain biking dropping into a steep valley. The sensor ensures the drone won’t descend until it has a clear path below it. We like this top-quality video showing AirDog II in action!

IFM (Intelligent Flying Machines)

TeraRanger distance sensors are assisting Intelligent Flying Machines (IFM) with their mission to automate indoor data capture. The exciting startup uses small and lightweight aerial systems to provide real-time inventory counting in warehouses, helping to improve the operational efficiency of manufacturing and logistics enterprises.

IFM uses computer vision and machine learning to collect data, navigating in close range to pallets and racking systems with centimeter accuracy. For this to work, fast and consistent altitude control of the drone is essential. After extensive testing, IFM selected the TeraRanger One distance sensor. “We are aware that aerial indoor navigation is highly complex, so we were after an altimeter that could provide our autopilot with fast and accurate distance data, and one that could still be physically integrated in our small platforms” says Marc Gyongyosi, CEO at IFM.

”TeraRanger One provides a reference point to position the flying robot at the necessary altitude at high speed within the warehouse. In fact, this contributes to our objective of autonomously turning over an entire warehouse in less than 20 minutes”. Marc continues, “It is impressive how all this high-performance sensing has been squeezed into a sensor that weights only 8 grams.”

Precision altimeter TeraRanger One

Squadrone System

After launching the Hexo+ drone in 2014, and selling over 3000 units worldwide, Squadrone System is now providing drone solutions to solve industrial problems. These include warehouse inventory management, insurance assessment for agriculture claims and a drone dedicated to the security of sensitive sites.

Antoine Level, CEO at Squadrone says: “TeraRanger proved to be the ideal precision altimeter, enabling our drones to hold a steady altitude while gathering high-quality data. We use TeraRanger One on our current platforms. The low power consumption and sensor performance is ideally suited to our needs.”

Drone precision altimeter


We are pleased to support Chouette on their quest to keep every vineyard healthy! Thanks to their drone-based monitoring solution, it is possible to prevent the spread of diseases that could potentially ruin hectares of vines and months of work. They’ve created this video showcasing their drone-based monitoring solution using TeraRanger One drone precision altimeter.

High performance without using laser!

Instead of laser, TeraRanger One uses eye-safe LED technology. One advantage of this is that it enables the sensor to have a “Field of View” so that, rather than measuring distance based on a tiny point of light, the sensor measures over an area. At 1m distance the area is approximately 3cm by 3cm. At 10m it is approximately 30cm by 30cm, increasing linearly with range. In an altimeter and anti-collision application this is a significant advantage and provides a more appropriate and stable data stream. Rather than distance readings jumping up and down as you fly over a crop, alternating between the ground and the crop, instead the sensor streams a stable flow of distances in millimeters. If the sensors were mounted radially, for collision avoidance for example, and you were flying close to trees, TeraRangers’ Field of View means you are far more likely to ‘see’ the trees and be able to avoid them. A laser, by contrast, would be likely to ‘see’ the gaps between leaves and branches and look out to infinity or an object behind the tree.

Featured product: TeraRanger One

Click “Learn More” for specification sheets, user manuals, software and other resources.

Fast and complex aerial maneuvers – no problem for TeraRanger One!

TeraRanger One is the ideal solution for us” says Alexis Lussier Desbiens, Professor of Robotics and Mechanical Engineering at Sherbrooke University, whose team has developed a fixed-wing flying robot that lands on vertical walls! The S-MAD 

drone land on vertical walls

(Sherbrooke’s Multimodal Autonomous Drone) uses a thrust-assisted landing technique to reliably land on vertical walls, and then take-off again. To achieve this, they mounted a TeraRanger One distance sensor on the airframe to quickly identify vertical surfaces before pitching S-MAD into a vertical plane for approaching and‘perching’ on the wall. Alexis continues: “Thanks to the sensor’s small and lightweight design – we could easily integrate it on the S-MAD, while the fast update rate gave us the confidence to repeatedly launch the drone at concrete walls!”. Terabee’s optical LED Time-of-Flight technology for range sensing provides data refresh rates as high as 1000 readings per second, performing as well as, and often better, than laser systems but in a far smaller, lighter (only 8g) and less expensive form-factor.

For this type of creative aerial technology, there are many potential applications, including indoor and outdoor inspections of difficult-to-access locations, or long duration surveillance.
The team from Sherbrooke has provided us with a great video demonstrating both S-MAD and TeraRanger One in action: 

You can read more about the project on IEEE Spectrum. It’s a good article, even if they did refer to our technology as ‘laser’ rather than LED!

Featured product: TeraRanger One

Click “Learn More” for specification sheets, user manuals, software and other resources.

Meet Bo, the new mobile robot equipped with TeraRanger Multiflex!

Distance sensors

Safely navigating a cluttered and constantly changing environment is not without its challenges! In this video you’ll see Bo – a cool new social robot from the team at Botsandus – performing a number of navigation and collision avoidance scenarios using TeraRanger Multiflex sensing system for robots.

Meet Bo!

Mobile robot navigation with TeraRanger Multiflex

Mobile robot navigation with TeraRanger Multiflex

Bo is a state of the art robot with advanced human-robot-interaction capabilities. Bo revolutionises customer experience across events, hospitality and retail sectors with its approachable design and large, easy to use touchscreen panel and audio interaction. The robot’s main objective is to seamlessly move through a restaurant or exhibition hall and share relevant information to customers. But to do so – without crashing into chairs, tables, walls and people – it is essential to feed Bo with information about the rapidly and constantly changing environment. To assist with this, the team at Botsandus selected TeraRanger Multiflex.

Andrei Danescu, Botsandus CEO explains; “We have integrated the 8 sensor Multiflex kit in a 360-degree configuration to perform ‘sense and avoid’ for obstacles within a 2 meter range. For us, Multiflex is a far better option than the ultrasound sensors we’d been considering. Not only is Multiflex really easy to use, but it provides a faster and more reliable stream of data.”

See Bo – and his TeraRanger Multiflex sensors – in action in this short video.

Featured product: TeraRanger Multiflex

Click “Learn More” for specification sheets, user manuals, software and other resources.

Traffic monitoring with TeraRanger One distance sensor

Traffic monitoring

TeraRanger sensors: Faster than a travelling car!

traffic monitoringWhilst our sensors are well known in the robotics and automation sectors, they are also beneficial for Internet of Things and other ‘smart’ applications. In this short white paper we show how a low-cost TeraRanger One distance sensor can be used for traffic monitoring, not only to detect the presence of a vehicle, but to also add an extra level of intelligence, simply using distance measurements.

How did we do it?

With up to 1000 distance readings per second, not only could we count the cars passing at 110km/h, we could also get a representation of their size and profile!

Discover more and see the results in this free white paper.

If you require solutions for IoT applications, people, traffic or object monitoring, please contact us. We’ll be happy to explore the opportunity with you.

Featured product: TeraRanger One

Click “Learn More” for specification sheets, user manuals, software and other resources.